As described in U.S. Pat. No. 5,357,998, which is incorporated by reference herein, there is a risk of conduit failure when working with high-pressure fluids.
When filling containers with compressed gasses or fluids or operating equipment that relies on high-pressure fluid flow or compressed gas, it is necessary for the fluid/gas to be transferred from one container to another. Although the fluid/gas can be transferred from one container to another using solid piping, it is common in many situations to use a flexible conduit or hose attached between the containers. A flexible hose allows ease of connection/disconnection of containers, as well as a limited range of motion between source and destination.
For example, compressed gas such as oxygen, nitrogen, carbon dioxide and the like are transported, stored and used in individual cylinders of varying size. In order to fill these cylinders with the desired compressed gas, it is necessary to connect each cylinder to a filling station manifold (either singly or in groups) at the location of a gas filler/seller. In order to connect each cylinder to the filling station manifold, a flexible hose is used to allow for quick connection/disconnection of the cylinders to the manifold. In addition, operating equipment that runs or uses compressed gas (such as forklifts) or pressurized fluids (such as hydraulic systems) also benefit from the ease of use of flexible hose.
Hoses can fail, however, even though they are generally made from durable yet flexible materials/constructions, such as treated and reinforced rubber, neoprene, nylon, TEFLON.TM., stainless steel and others. Hose failures can occur from a number of causes, including ruptures and splits/cuts. When a hose fails, it can cause substantial damage in a number of ways. First, if a hose is completely severed or split, both ends of the hose can whip around wildly under the forces of the compressed gas or fluid, now exerted from the delivery end and the receiving end. In addition, if a cylinder is not secured, the pressure of the gas or fluid leaving the cylinder can cause the cylinder to move very rapidly in the opposite direction of the gas/fluid. Both of these situations can result in substantial risk of personal injury, as well as property damage. Still further, a hose failure will cause a leak from both the delivery and receiving ends, leading to a costly waste of gas or fluid, the discharge of hazardous gas or fluids, as well as the potential of filling the environment with hazardous fumes.
U.S. Pat. No. 5,357,998 discloses a successful fluid conduit safety system that uses a flexible, yet relatively stiff cable disposed inside of a hose to maintain single valve bodies at either end of the hose in an open position during normal or open operation. When a failure condition, such as a rupture, cut, separation or stretch of the hose occurs, the valve bodies are able to seat with the valve seats, sealing both ends of the hose. This prevents fluid/gas leaks from both sources (i.e. cylinder and filling apparatus). When a failure occurs, the flexible, yet relatively stiff cable may be severed, allowing the fluid pressure to force the valve bodies into engagement with the valve seats. If a hose failure does not sever the cable, the valve seats are either forced into engagement with the valve bodies or the valve bodies are forced into engagement with the valve seats. In either circumstance, a seal is accomplished by seating the valve bodies with the valve seats.